Behavior and gustatory reception of air-breathing catfishes (Clariidae)

Abstract

Taste preferences to classical taste substances and L isomers of free amino acids and feeding behavior are analyzed in clariids Clarias gariepinus, C. macrocephalus, and C. batrachus and the hybrid between C. macrocephalus (female) and C. gariepinus (male). It is found that citric acid (0.26 M) is palatable for all studied clariids, and the presence of this acid in agar-agar pellets considerably increases their con sumption by fish. The stimulating effect of citric acid on C. gariepinus and C. macrocephalus is greater than the effect of water extracts of organisms consumed by these species or of artificial foods. Sucrose (0.29 M) is palatable for both species. The palatability of sodium chloride (1.73 M) and calcium chloride (0.9 M) is the same for C. gariepinus and the hybrid but different for C. macrocephalus (p < 0.05), indicating the patroclinous type of taste preference inheritance. Of the 21 free amino acids (0.1-0.001 M), 17 are palatable for C. gariepinus (methionine, alanine, glutamine, cysteine, histidine, etc.) and four are indifferent (arginine, leucine, isoleu cine, and tryptophan). No amino acid is found to be deterrent for the studied fishes. All studied fishes typi cally consume or reject pellets after a single intraoral testing; repeated grasping of pellets is extremely rare. The total time clariids spend on intraoral testing and consumption or rejection of one pellet is at most 3-5 s. Clariids captured in their natural environments (C. macrocephalus and C. batrachus) require considerably more time for acclimation to aquarium conditions than clariids taken from the aquaculture (C. gariepinus and the hybrid): at least one month and several days, respectively. The stress response to handling in wild fish includes the release of large amounts of skin mucus.

Taste Preferences and Orosensory Feed Testing Behavior in Barramundi Lates calcarifer (Latidae, Perciformes)

“…In more than three dozen species studied in previous research, taste preferences have been assessed mainly in fish that inhabit water bodies in the temperate (boreal) climate zone [13]. For tropical fish, such data are known only for a few freshwater species, including marble goby, Oxyeleotris marmoratus; pearl gourami, Trichopodus leerii, and three spot gourami, T. trichopterus; Nile tilapia, Oreochromis niloticus; and North African catfish, Clarias gariepinus [23][24][25][26][27][28]. For marine tropical fish, taste preferences have been studied for grouper Epinephelus fuscoguttatus and the hybrid grouper E. fuscoguttatus × E. lanceolatus [29,30].…”

“…These amino acids are more often among those most attractive to different fish: cysteine for 18 tested species and alanine for tested 20 species [31]. As with barramundi, both cysteine and alanine have a taste that is attractive to common carp, Cyprinus carpio; tench, Tinca tinca; stellate sturgeon, Acipenser stellatus; North African catfish; and three spot gourami [23,28,[32][33][34]. However, there are species that refuse to consume pellets if cysteine or alanine is presentthese include goldfish, Carassius auratus; European minnow, Phoxinus phoxinus; Siberian sturgeon, Acipenser baerii; chum salmon, Oncorhynchus keta; and Arctic char, Salvelinus alpinus erythrinus [34][35][36][37][38].…”

Taste preferences and feeding behaviour in the facultative herbivorous fish, Nile tilapia Oreochromis niloticus

“…Nonetheless, most often (>95% of trials), a single grasp was enough for O. niloticus to make the final decision concerning edibility of any types of pellets. Such behaviour pattern is attributable for fishes with poor vision or living in the water current and minimizes the risk of food loss (Kasumyan, 2014). Tilapias avoid rapids and fast‐flowing waters but tolerate high water turbidity (Philippart & Ruwet, 1982), an environmental condition that increases the risk of losing food items, too.…”